[evlatests] Maser Tomorrow

[Keith Morris]

We have been monitoring and adjusting the drift rate of the Maser since 
it was installed at the VLA site two weeks ago.  A frequency adjustment 
was made yesterday morning, and the drift rate since then is 
unmeasurable at the resolution of this monitor point, which means less 
than 8ns/day.  More importantly, the rate appears to be stable.  I 
recommend that we switch the system back to Maser during tomorrow's 
maintenance day.

This means that we will need to resynchronize, since the difference 
between the maser offset to GPS and the rubidium offset to GPS will 
likely be greater than the sync detect window in the L350.  Presently, 
the Rubidium offset to GPS is around 76us (leading), and the drift is 
accelerating.

If anyone objects to this, please let me know.  Otherwise we will 
proceed tomorrow.  If it is decided that we should *not* make the 
switch, then I would recommend that we make another frequency adjustment 
to the Rubidium.  I am coordinating with Kerry to avoid conflicts with 
the correlator testing.


-- 
Keith Morris
National Radio Astronomy Observatory
1003 Lopezville Rd.
Socorro, NM 87801
575-835-7060 (phone)
575-835-7027 (fax)